The services provided by the current telecommunication network are become more and more integrated, and with the higher and higher integration ability of telecommunication equipment, call loss of large area may occur once any abnormity appears in the equipment, therefore, the secure and reliable operation of the network becomes very important.
In the current switch network, a service and switch unit includes a switch, an SS (Soft Switch), an SCP (Service Control Point), and an AS (Application Server). Since the covering area is large, the secure intercommunication between the soft switch and the other network elements has become a problem that both the operators and the manufacturers focus on. Now, there are various solutions for the secure intercommunications between the soft switch and the smart network SCP, and between the soft switch and the AS.
In a first-class toll network constituted by soft switches, there are particular requirements for the security problem of the communication between soft switches due to the particularity of the network.
FIG. 1 shows a network topological graph of a first-class toll network constituted by soft switches in the prior art A soft switch SS1, and a soft switch SS2-1 and a soft switch SS2-2 are respectively located in different provinces, the soft switch SS1 centrally connects calls in a large district 1 (a plurality of provinces constituting a large district), the soft switch SS2-1 and the soft switch SS2-2 centrally connect calls in a large district 2; the soft switch SS1 and the soft switch SS2-1 and the soft switch SS2-2 are interconnected, each of which has a TMG (Trunk Media Gateway), i.e., TMG1, TMG2-1, and TMG2-2, respectively.
FIG. 2 shows a network topological graph of another first-class toll network constituted by soft switches in the prior art A soft switch SS1, and a soft switch SS2-1 and a soft switch SS2-2 are respectively located in different provinces, the soft switch SS1 centrally connects calls in a large district 1, and the soft switch. SS2-1 and the soft switch SS2-2 centrally connect calls in a large district 2; the soft switch SS1 and the soft switches SS2-1 and SS2-2 are interconnected, and the two soft switches SS2-1 and SS2-2 in the large district 2 only have one TMG2-1.
As illustrated in FIG. 1 and FIG. 2, since the traffics centrally connected by respective soft switches are quite high, in the case that fewer TMGs are configured, it should be ensured that tee tandem between the large districts will not be influenced when a TMG fails.
Please refer to FIG. 3 as well, which shows a secure intercommunication solution between soft switches in the prior art.
In this prior art the backup disaster-recovery of the core routing device is realized by a router 301 and a router 302, that is, the two first sub-routes are backups in terms of physical device. Furthermore, in the case of the interruption of the direct routes (i.e. the first sub-routes) of the two soft switches SS1 and SS2, a call is transferred to a switch 304 via a second sub-route.
That is to say, the disaster recovery solutions for solving the service interruption between soft switches at present have two strategies: (1) disaster recovery is realized by network equipment; and (2) in the case of the failure of all network equipments, a call is guaranteed to be normal by a second sub-route. In particular; the strategy 1 is to perform the backup disaster-recovery by hardware, the soft switch provides an IP interface through an interface board of primary backup or load sharing, and the bearer network accesses the soft switch of the opposite end via two different IP channels. The strategy 2 identifies the failure of the first sub-route by the soft switch of the local end, and answers the call to the soft switch of the opposite end via the second sub-route directly.
The secure intercommunication solutions in the prior art can prevent the problem of service interruption caused by the failure of the route between soft switches. In particular, in the above prior art, when the soft switch detects that the first sub-routes are unavailable via the hardware and protocol of the local end, it does not select the sub-routes during a call, and transfers the call directly via the second sub-route. However, the deficiency of the above prior art lies in failing to consider the situation of service interruption caused by the failure of the TMG of a soft switch or the full blocking of office-directed tails occurring at the opposite end. Therefore, when the failure of the TMG of a soft switch or the full blocking of office-directed trunks occurs at the opposite end, since the soft switches will continue to transfer the call in the selected sub-route, the complete interruption of services between large districts may occur in the first-class toll network constituted by soft switches. To be brief, in the soft switch networks of the prior art only the situation of the route failure between soft switches is considered, whereas the situation of the route failure at the soft switch of the opposite end is not taken into account.
Consequently, there is a need for a security protection method and apparatus for performing security protection during service interruption occurring in a switch network which can prevent the occurrence of the complete interruption of services between large districts in a first-class toll network constituted by soft switches when the failure of the TMG of a soft switch or the full blocking of office-directed bunks occurs at the opposite end.